Commit 06ed63e2 authored by David Fifield's avatar David Fifield
Browse files

Add a DialOrWithDialer function. 

The intention of this is to permit setting a source address to avoid
ephemeral port exhaustion on servers with many connections.

https://bugs.torproject.org/tpo/anti-censorship/pluggable-transports/snowflake/40198#note_2839304
https://bugs.torproject.org/tpo/anti-censorship/pluggable-transports/snowflake/40201#note_2839433
parent 7075f159

pt.go

+20 −7
Original line number Diff line number Diff line
@@ -1000,20 +1000,20 @@ func extOrPortSetup(s net.Conn, timeout time.Duration, 
	return nil

}



// Dial info.ExtendedOrAddr if defined, or else info.OrAddr, and return an open

// *net.TCPConn. If connecting to the extended OR port, extended OR port

// authentication à la 217-ext-orport-auth.txt is done before returning; an

// error is returned if authentication fails.

// Dial (using the given net.Dialer) info.ExtendedOrAddr if defined, or else

// info.OrAddr, and return an open net.Conn. If connecting to the extended

// OR port, extended OR port authentication à la 217-ext-orport-auth.txt is done

// before returning; an error is returned if authentication fails.

//

// The addr and methodName arguments are put in USERADDR and TRANSPORT ExtOrPort

// commands, respectively. If either is "", the corresponding command is not

// sent.

func DialOr(info *ServerInfo, addr, methodName string) (*net.TCPConn, error) {

func DialOrWithDialer(dialer *net.Dialer, info *ServerInfo, addr, methodName string) (net.Conn, error) {

	if info.ExtendedOrAddr == nil || info.AuthCookiePath == "" {

		return net.DialTCP("tcp", nil, info.OrAddr)

		return dialer.Dial("tcp", info.OrAddr.String())

	}



	s, err := net.DialTCP("tcp", nil, info.ExtendedOrAddr)

	s, err := dialer.Dial("tcp", info.ExtendedOrAddr.String())

	if err != nil {

		return nil, err

	}
@@ -1025,3 +1025,16 @@ func DialOr(info *ServerInfo, addr, methodName string) (*net.TCPConn, error) { 


	return s, nil

}



// Dial info.ExtendedOrAddr if defined, or else info.OrAddr, and return an open

// *net.TCPConn. If connecting to the extended OR port, extended OR port

// authentication à la 217-ext-orport-auth.txt is done before returning; an

// error is returned if authentication fails.

//

// The addr and methodName arguments are put in USERADDR and TRANSPORT ExtOrPort

// commands, respectively. If either is "", the corresponding command is not

// sent.

func DialOr(info *ServerInfo, addr, methodName string) (*net.TCPConn, error) {

	c, err := DialOrWithDialer(&net.Dialer{}, info, addr, methodName)

	return c.(*net.TCPConn), err

}